DENTALIUM-FISSIDENTALIUM. 79 



ornamented throughout its length with well developed unequal ribs, 

 rather narrow and nearly rounded on the dorsal surface, wider and 

 perceptibly flattened on the opposite surface, the interspaces a little 

 wider than the ribs. Growth striae oblique toward the base and 

 quite impressed, spaced and a little irregular, becoming straighter 

 and less visible toward the apex. Color dull gray above, passing 

 into slightly shining white toward the base. Length 95, greatest 

 diam. 17, curvature 10 mill. (Locard). 



West coast of Africa, Senegal, Sahara, Azores between Pico and St. 

 George, between 1258 and 3650 fms. 



D. exuberans LOCARD, L'Echange, Revue Linneenne, No. 146, 

 Feb., 1847, p. 10. 



The slit seems to be interrupted into a series of orifices as in D. 

 plurifissuratum and the young specimen of capillosum figured by 

 Watson, and the aperture is oval. 



D. SCAMNATUM ' Fischer ' Locard. 



Shell of relatively very large size, the contour narrowly and pro- 

 gressively conoid from base to summit, perceptibly curved through- 

 out the length ; base quite wide, with almost exactly circular aper- 

 ture, the plane of which is a little oblique. Apex slender, con- 

 tracted, slowly tapering ; apical slit narrow and long. Shell some- 

 what thin, quite solid, ornamented throughout with very fine longi- 

 tudinal costulations, which are regular, a little flattened, closely 

 crowded and very vaguely subgranulose, the intercostal intervals 

 shallow and very narrow as though linear. Concentric strise of 

 growth fine, crowded, scarcely regular, giving the costulse a sub- 

 granulose appearance. Color a light reddish-gray, sometimes paler 

 at base. Length 95, greatest diameter 9 mill., curvature 4 mill. 

 (Locard). 



West coast of Africa, Cape Ghir, the Azores, and Sargasso Sea, 

 in 1235-2087 meters. 



D. scamnatum P. Fischer, LOCARD, L'Echange, Revue Linneenne, 

 No. 146, Feb., 1847, p. 10. 



D. PROFUNDORUM E. A. Smith. PL 6, fig. 82. 



Shell large, solid, lightly arcuate, longitudinally very finely 

 striated and sculptured with oblique growth-lines; dull buff; pos- 

 teriorly slit. Aperture nearly circular, white inside, thin at the ob- 

 lique margin and acute. Length 90, greatest diam. 10 mill. 

 (Smith). 



